As a team leader in the Estuarine and Ocean Ecology Program of the Northwest Fisheries Science
Center, I have been involved with studies examining the habitat and ecology of
juvenile salmon when they first enter the ocean. Mortality appears to
increase dramatically in the first few months at sea and we still don't know the
mechanisms behind these losses. On a short "sabbatical" to a laboratory down in
California in 1998, I worked on a coast-wide research plan to
examine survival of juvenile salmon in the ocean. Presently, I am working as
part of a team that goes out and samples juvenile salmon in large trawls from
the Canadian border to northern California. We are comparing our results to
those observed during the early 1980s as part of a project under the direction
of Bill Pearcy at Oregon State University. My specific interests lie in the food
resource utilization of juvenile salmon, particularly in the selection of prey
and effects on prey resources (see Food Web Studies).

- Salmon research -

-Pelagic nekton studies-

As part of our research funded by
GLOBEC and
BPA, I and my
collaborators have been examining interannual and longer-term studies of
pelagic nekton and micronekton communities off of Oregon and throughout the
North Pacific. Nekton are defined as the fast moving, generally larger
fishes and squids that are usually caught in pelagic (near-surface zone)
trawls. These include the tunas, salmon, mackerels, herring and
smelts, anchovies and sardines, and a large number of other important
species. Micronekton are usually smaller and require special sampling nets
to capture them. They often include interesting fishes, squid and
crustaceans that inhabit the open oceans such as laternfishes, but also can
include juvenile fishes. We have attempted to use multivariate statistical
methods to define communities and then relate these to oceanographic
conditions in which the communities were caught and look at long term
changes in dominant species in relation to interdecadal changes in the
environment. We also can look at potential predation or competition among
the members of a community by examining their diets (see Food Web studies).

I have been involved in examining food web
relationships in the
Subarctic Pacific, Bering Sea and along the west coast of the United
States for the past 20 years. For my Master's thesis, I examined the
feeding ecology of five species of rockfishes over much of the coastal
Pacific Northwest, but particularly on their reliance on mesopelagic
prey advected onto an offshore bank. I continued on examining the
feeding and food web relationships of juvenile salmon in coastal waters,
looking at diet overlap with other nekton and food consumption in
relation to available prey resources. Many of these studies formed the
bulk of my dissertation research. Moving on to work on recruitment
studies in walleye pollock, I continued studies of the feeding ecology
of this species in both the Gulf of Alaska and Bering Sea. I examined
prey selection, diel feeding chronology and food consumption, and
variability in feeding with respect to physical factors such as fronts
and eddies. Returning to the West Coast, I continue to examine the
feeding ecology of juvenile salmon and other associated species by means
of stomach analyses and stable isotope ratios through our BPA and GLOBEC
funded projects. I also am interested in the effects of abrupt
topography in the form of banks or canyons as areas that concentrate
prey organisms for higher trophic levels such as rockfishes and have
worked in Pribilof Canyon in the Bering Sea, Astoria Canyon and Heceta
Bank off Oregon. My work in Astoria Canyon has been particularly
interesting as we documented the first occurrence of a mass mortality of
krill in the deep ocean as part of our Ocean Exploration program.

I have been involved with examining factors
underlying recruitment
variations in marine fishes for much of my career. Early on, I
examined variability in juvenile salmon survival in the coastal ocean
related to food availability, growth, and predators. While working
with the Fisheries Oceanography Coordinated Investigations in Seattle,
I was involved with a long-term study of factors related to year-class
strength in walleye pollock in the Gulf of Alaska and Bering Sea. I
examined distribution of eggs, larvae, and early juveniles in relation
to ocean features such as eddies and fronts. I also was interested in
other species that may interact with pollock as competitors or
predators in this region. I used immunoassays and gut content analyses
to examine vertebrate and invertebrate predation on pollock eggs and
larvae, and also conducted controlled laboratory studies on
predation. Since moving back to the west coast, I have continued to
look at recruitment in juvenile salmon, and am now starting to analyze
the full range of ichthyoplankton taxa off the coast to understand
recruitment processes in non-salmonid species.